Friends of Bankstown teen Abdullah Elmir have been left shocked after he appeared in a chilling new Islamic State video.
"We didn't expect him to do something like that cause he's an intelligent student, but I guess he got brainwashed or something,” school friend Saeed Saadie said.
Before he was a Jihadist, Elmir was a schoolboy at Sydney's Condell Park High.
"When anyone needed help, he was the person to rely on,” school friend Adam Hafza said.
"It was only recent he started getting into the whole really extremist sort of thing,” student Moiz Iftikhar said.
His video was made for maximum impact at home.
"To Tony Abbott I say this, we will not stop fighting, we will not put down our weapons,” Elmir announced in the video.
It's had mixed reviews.
In some states teachers have been warned to look out for sudden changes in students' behaviour as a warning sign that they are being radicalised.
But 7News spoke to people at Elmir’s high school who said while he was a deeply religious Muslim, there was no sign he planned to join extremists.
"Australia has not got an intervention program. So those people who are on the cusp of radicalisation, currently we have no resources to pull those people back into line,” Sydney Muslim spokeswoman Lydia Shelley said.
Experts believe Elmir is mixing with former Sydney terrorist Mohamad Elomar seen in shocking photos with severed heads.
"Those people who are holding him and brainwashing him - they're not going to allow him to come back,” Muslim community leader Dr Jamal Rifi said.
Ms Shelly said: “It is incredibly important more now than ever that we do not allow those videos to destroy us, to rip us apart.”